The invention relates to a process for manufacturing an injection device of the pre-filled type containing a dose of liquid for injection. It extends to an injection device produced according to this manufacturing process.
Currently all the pre-filled syringes on the market have a cap, intended to protect the needle prior to use, which is removed for the injection to be administered and then replaced after injection so as to prevent the subsequent risks of pricking with the soiled needle.
A design of this kind has a major disadvantage arising from the fact that when re-capping the needle, the cap must be offered up opposite the end of this needle. This requirement is in fact the cause of relatively frequent accidents due to pricking, with all the risks that such pricks from a soiled needle involve. Furthermore, such syringes offer no safeguard whose purpose is to prevent their re-use and must therefore be the subject of special care as regards their destruction.
Despite these crucial disadvantages, no rational solution, either from the point of view of industrial-scale manufacture or from the point of view of ease of use of the syringes, has as yet been put forward in respect of pre-filled syringes, which aims to equip them with a protection system suitable for avoiding the risks of pricking after use and preventing further use.
The purpose of the invention is to mitigate these disadvantages and its substantial object is to provide an injection device of the pre-filled type with a low cost price and designed to avoid any risk of pricking after use and to prevent any subsequent re-use.
A further object of the invention is to provide a less costly injection device combining the above-mentioned advantages and incorporating a traditional pre-filled syringe of the type currently in use.
A further object of the invention is to provide an injection device permitting the liquid to be injected to be isolated from the injection needle up to the time of the injection.
A further object of the invention is to provide an injection device having a very low "dead" volume and thus enabling very small doses of liquid to be injected.
A further object of the invention is to provide an injection device particularly suitable for permitting an injection requiring the syringes to be held in an inclined position with respect to the point of injection.
To this end the invention provides a process for manufacturing a pre-filled injection device comprising an injection needle, comprising:
producing a tubular syringe body of a deformable plastics material, equipped towards one of its ends, called the rear end, with finger-hold elements and towards its other end, called the front end, with an external locking element suitable for deforming radially between a retracted position and a dilated position, PA1 producing a tubular sheath of a shape suitable for being able to slide along the syringe body, comprising an internal locking element paired with that of the said syringe body in the dilated position of this latter, arranged towards one of its ends, called the rear end, PA1 offering up the rear end of the sheath opposite the front end of the syringe body and causing the said sheath and syringe body to slide with respect to each other, this sliding being permitted thanks to the radial retraction of the locking element of the said syringe body, so as to bring the rear end of the sheath to rest adjacent to the finger-hold elements of the syringe body in a position, called the injection position, in which the said sheath extends externally along the syringe body and in which at least the front end of the said syringe body is disengaged, PA1 introducing into the syringe body a rigid pre-filled container of external cross-section paired with the internal cross-section of the syringe body suitable for bringing the external locking element of the syringe body into its dilated position and preventing any further radial deformation of the said locking element, the said rigid container being equipped with means for injecting the liquid contained in the latter, PA1 and locking the tubular body and the rigid container in translation with respect to each other. PA1 the assembly of which is obtained, initially, by a simple sliding of the said syringe body and sheath with respect to each other, this sliding being permitted by the radial retraction of the external element of the syringe body, PA1 then forming a non-deformable structure thanks to the introduction into the interior of the syringe body of a rigid container designed radially to dilate the external element of the said syringe body and prevent any subsequent radial deformation of the latter, thus guaranteeing an irreversible locking of the sheath in its advanced position. PA1 the windows provided in the sheath and the syringe have the sole function of enabling the dose container to be seen, PA1 this dose container is not a rigidifying element intended to ensure that the sheath is irreversibly locked in its advanced position, since because of the design of the locking elements, this irreversible locking is obtained whether the dose container is housed in the syringe body or not. PA1 a syringe body is produced which is equipped with a front end having the form of a sleeve, PA1 a rigid container comprising a pre-filled syringe with an injection needle and having a front portion of a shape suitable for being accommodated in the sleeve of the syringe body, so that the injection needle extends in the extension of the said syringe body, is introduced into the syringe body. PA1 a syringe body is produced which is equipped towards its front end with a nose pierced longitudinally by a bore of cross-section suitable for accommodating an injection needle, PA1 an injection needle is introduced into the bore of the nose of the syringe body, so that it has an active injection portion in the extension of the said syringe body, and a piercing portion opening into the interior thereof, PA1 the injection needle is secured in the bore of the nose of the syringe body, PA1 and a rigid, pre-filled container equipped with a sealing element suitable for being pierced by the piercing portion of the injection needle is introduced into the syringe body. PA1 a syringe body is produced which is equipped with a front end sealed by a front end wall pierced by an aperture, and comprises a longitudinal bore, arranged in its peripheral wall, extending between the said front wall and a radial internal duct opening in the interior of the said syringe body, this radial duct being arranged at a distance from the front wall and being juxtaposed longitudinally to a shoulder delimiting, inside the syringe body, an end chamber, incorporating the said radial duct, of smaller cross-section than the standard internal cross-section of the said syringe body, PA1 an injection needle is introduced into the longitudinal bore so that it has an active injection portion in the extension of the front wall of the syringe body, PA1 the injection needle is secured in the longitudinal bore of the syringe body, PA1 and into the interior of the syringe body is introduced a rigid pre-filled tube of cross-section suitable for coming to rest against the internal shoulder of the said syringe body, the said rigid tube being sealed, towards each of its ends, by a sliding plug, respectively called front and rear, the front plug having a shape suitable for being accommodated in the end chamber of the syringe body, when the rear plug slides, in a position in which it comes to rest against the front wall and disengages the radial duct. PA1 a tubular syringe body made of a deformable plastics material, equipped towards one of its ends, called the rear end, with finger-hold elements and towards its other end, called the front end, with an external locking element suitable for deforming radially between a retracted position and a dilated position, PA1 a tubular sheath of internal cross-section suitable for being able to slide along the syringe body, equipped with an internal locking element paired with that of the said syringe body in the dilated position of this latter, arranged towards one of its ends, called the rear end, the said sheath being suitable for being able to slide between two positions: PA1 a rigid pre-filled container introduced into the interior of the syringe body and of external cross-section paired with the internal cross-section of the said syringe body, PA1 and means for the relative locking in translation of the rigid container and the syringe body. PA1 the locking element of one of the components, syringe body or sheath, has the form of an annular boss comprising an annular groove and notches, arranged either side thereof, PA1 the locking element of the other component, sheath or syringe body, comprises an annular rib delimiting a section paired with the section of the bottom of the groove of the boss of the first component. PA1 the syringe body comprises a front end having the form of a sleeve, PA1 the pre-filled rigid container comprises a pre-filled syringe having an injection needle, and having a front portion of a shape suitable for being accommodated in the sleeve of the syringe body, so that the injection needle extends in the extension of the said syringe body. PA1 the syringe body is equipped, towards its front end, with a nose pierced longitudinally by a bore accommodating an injection needle so that the latter has an active injection portion in the extension of the said syringe body, and a piercing portion opening into the interior thereof, PA1 the rigid, pre-filled container comprises a cartridge equipped with a sealing element suitable for being pierced by the piercing portion of the injection needle. PA1 the syringe body is equipped with a front end sealed by a front end wall pierced by an aperture, and comprises a longitudinal bore arranged in its peripheral wall, housing an injection needle so that the latter has an active injection portion in the extension of the front wall, the said bore extending between the said front wall and a radial internal duct opening in the interior of the said syringe body, this radial duct being arranged at a distance from the front wall and being juxtaposed longitudinally to a shoulder delimiting, inside the syringe body, an end chamber incorporating the said radial duct, of smaller cross-section than the standard internal cross-section of the said syringe body, PA1 the rigid pre-filled container comprises a cartridge of cross-section suitable for coming to rest against the internal shoulder of the said syringe body, the said cartridge being sealed, towards each of its ends, by a sliding plug, respectively called front and rear, the rear plug performing the function of plunger, and the front plug having a shape suitable for being accommodated in the end chamber of the syringe body, when the rear plug is actuated, in a position in which it comes to rest against the front wall and disengages the access to the radial duct.
The process according to the invention thus comprised producing a syringe body and a sheath:
The manufacture of an injection device according to the invention is thus achieved in two very simple operations each comprising causing an element to slide longitudinally with respect to another. Manufacture of this kind can therefore easily be automated and lead to a high rate of production of injection devices having a low cost price.
Furthermore, the injection device produced is designed to prevent any risk of accident. In fact, it is equipped with a protection sheath caused to slide towards the front, once the injection has been administered, without any risk of pricking because the needle is re-covered by moving this sheath in the direction of the front end of the syringe body. In addition, once it is in its advanced position this sheath is locked in translation with respect to the syringe body, thus preventing any re-use of the injection device.
It should also be noted that the rigid container, which performs the particular function of making the syringe body rigid, can be put in place either in a preliminary phase at the time of manufacture or solely at the time of use of the injection device.
It is appropriate to stress that the international patent application WO-95 04 565 describes a suction syringe comprising a protection sheath, and of which a priori the sheath is caused to slide along the syringe in order to assemble these elements.
Nevertheless, the syringe is produced from a rigid plastics material and also has a rectangular cross-section, and so it cannot be deformed radially, unlike that of the invention.
In practice therefore, the sheath can only slide along the syringe either if this syringe is deformed by nipping by a mechanical or manual action, or the rear lugs 30, 31 of the sheath are spread by a mechanical or manual action.
Furthermore it should be noted that this patent specifies that:
In fact, even if this patent describes an injection device whose manufacturing process has certain similarities with that of the invention, the general concept on which the invention is based differs totally from that of the process of this patent.
According to a first preferred embodiment, a syringe body is produced comprising a peripheral wall equipped with at least one longitudinal slot opposite the external locking element, suitable for permitting the radial deformations of the said locking element.
In this case the radial deformations of the external element of the syringe body are permitted thanks to the presence of at least one slot, which leads this external element to retract so as to enable the internal locking element of the sheath to pass and then to dilate when the rigid container is introduced.
According to a second preferred embodiment, a syringe body is produced comprising a front end portion in the shape of a truncated cone of decreasing cross-section in the direction of the front end of the said syringe body, and on which the external locking element is arranged, the said truncated-cone-shaped portion being equipped longitudinally with weakness zones suitable for permitting its radial dilation.
In this case the front end of the syringe body is pre-formed, when the said syringe body is moulded, so as to form the external locking element in a retracted position permitting the internal locking element of the sheath to pass, the presence of weakness zones enabling this external locking element to be brought into its dilated position radially when the rigid container is introduced.
According to a preferred embodiment intended to prevent any untimely sliding of the sheath before and during the injection, the respective rear ends of the sheath and of the syringe body are secured, in their injection position, by holding means suitable for being able to yield under the effect of a longitudinal tensile force applied to the sheath and intended to make it slide towards the front with respect to the syringe body.
Such holding means may comprise either paired enclosing structures provided at the respective rear ends of the sheath and of the syringe body, enabling them to be secured in a detachable manner. They may also comprise at least one securing point achieved by any per se known method such as heat welding, ultrasonic welding etc.
According to a first preferred embodiment:
This embodiment enables an injection device to be produced which comprises, by way of rigid container, a traditional pre-filled syringe like the current glass syringes, whilst equipping the said syringes, at reduced cost, with a protection system which guarantees against any risk of accident after use.
According to a second preferred embodiment:
This embodiment enables an injection device to be produced which comprises, by way of rigid container, any traditional container whose sealing system can be pierced by a needle in order to administer the injection. A container of this kind can thus comprise a simple cartridge of the type used, for example, in the dental field.
According to a third preferred embodiment:
This embodiment enables injection devices to be produced which have a very low "dead" volume, particularly suitable for injecting very small doses of liquid.
Furthermore, because of the position of the injection needle arranged laterally with respect to the syringe body, and by means of a correct orientation of the chamfer of the active injection portion thereof, this injection device is particularly suitable for permitting an injection (in the abdomen for example) which requires the injection needle to be held in an inclined position with respect to the injection point.
Furthermore, for each of the above-mentioned applications, the front end of the syringe body is advantageously capped, in traditional manner, in order to protect the needle prior to use and to prevent any risk of pricking with the latter.
The invention extends to an injection device of the pre-filled type comprising:
a rear, injection, position in which the rear end of the sheath rests adjacent to the finger-hold elements of the syringe body on the one hand, and at least the front end of the syringe body is disengaged on the other hand, PA2 a front, post-use protection, position in which the respective locking elements of the sheath and of the syringe body are in a state of cooperation on the one hand, and the sheath covers the front end of the syringe body and extends in the extension thereof on the other hand,
According to a first preferred embodiment the syringe body comprises a front end portion of decreasing cross-section in the direction of the front end of the said syringe body, on which portion the external locking element is arranged, the said truncated-cone-shaped portion being equipped longitudinally with weakness zones suitable for permitting its radial dilation.
According to a second preferred embodiment the syringe body comprises a peripheral wall equipped with at least one longitudinal slot extending opposite the external locking element, suitable for permitting the radial deformations of the said external locking element.
In this case, furthermore, the syringe body advantageously has a peripheral wall equipped with two diametrically opposed longitudinal slots. This arrangement of longitudinal slots is in fact advantageous when the syringe bodies are produced by plastic moulding.
According to a further feature of the invention:
Furthermore, the notches of the locking element arranged on one of the components, syringe body or sheath, and located towards the end of the said component, advantageously have a thickness greater than that of the second notches delimiting the groove of the said locking element.
As a result, the first notches cause a radial deformation of the syringe body which facilitates the passage of the second notches and ensures an easy fitting of the sheath on the said syringe body.
Furthermore, according to a further feature of the invention, the second notches of the locking element arranged on one of the components, syringe body or sheath, have a front face which extends according to a chord of the said component and is suitable for obtaining at the said notches a perimeter at least equal to that of the other component opposite the latter's annular rib.
The sheath is thus simply deformed triangularly on the passage of the second notches over the annular locking rib, without having to be radially dilated in order for this passage to take place, which facilitates bringing the said sheath into its advanced locking position, after use.
According to another feature of the invention the syringe body has an internal diameter appreciably larger than the external diameter of the rigid container, and comprises longitudinal internal ribs opposite the internal locking element of the said syringe body, determining a diameter paired with the external diameter of the rigid container.
This arrangement enables a label to be placed round the rigid container and an intimate contact between the syringe body and the rigid container to be obtained when the latter is introduced, despite the extra thickness that this label forms.
According to a first preferred embodiment of this injection device:
Furthermore, when the pre-filled syringe is traditionally equipped with a rear end comprising a finger-hold flange, the syringe body then preferably comprises, at its rear end, radial notches suitable for accommodating the said flange and for ensuring the locking in translation of the said pre-filled syringe.
Furthermore, the radial notches are preferably arranged in a cup-shaped ring of a diameter greater than that of the syringe body and arranged in the rear extension of the said syringe body, the said ring being suitable for serving as a frontal rest for the rear end of the sheath.
The injection device advantageously also comprises an annular deformable band arranged to be acted on by the flange of the syringe, so as to ensure a play-free locking thereof in the radial notches.
The advantage of such a band is to ensure a perfect locking of the syringe, despite the variations in thickness of the latter's flange due to manufacturing tolerances.
According to a second preferred embodiment of this injection device:
Furthermore, the sealing element of the cartridge preferably then comprises a plug suitable for being pierced and arranged, in an initial phase, so as to be at a distance from the end of the piercing portion of the injection needle, the said cartridge being sealed towards its other end, by a second plug performing the function of plunger.
An arrangement of this kind enables the liquid to be injected to be isolated from the injection needle up to the time of the injection. As a result and initially, this liquid is not in contact either with the needle or the adhesive used to secure it, and so is not at risk of contamination. Furthermore the needle does not have to be sealed, such as in the traditional manner by inserting it into the bottom of a cap, and its penetration qualities are therefore wholly preserved.
According to a further feature of the invention which provides this second preferred embodiment, the syringe body comprises, at its rear end, an internal rib suitable for ensuring the locking in translation of the cartridge introduced into the said syringe body.
According to a third preferred embodiment of this injection device:
An injection device of this kind has a very low "dead" volume and is particularly suitable for injecting small doses of liquid. Furthermore, it enables the liquid to be injected to be isolated from the injection needle up to the time of the injection.
Furthermore, the syringe body then preferably comprises, at its rear end, an internal rib suitable for ensuring the locking in translation of the cartridge introduced into the said syringe body.
Further features, objects and advantages of the invention will emerge from the detailed description below with reference to the accompanying drawings which show five preferred embodiments thereof by way of non-exhaustive examples. These drawings form an integral part of this description and are as follows: